Cuprous copper and/or silver halophosphate glasses

ABSTRACT

This invention is related to the production of glasses having compositions within the copper and/or silver-halide-phosphate field, wherein at least one halide is present selected from the group of fluoride, chloride, bromide, and iodide, such glasses exhibiting softening points below about 400° C., coefficients of thermal expansion (25°-300° C.) in excess of about 180×10 -7  /°C., high electrical conductivity, and electrochromic behavior. The copper-containing glasses may also demonstrate thermochromic properties.

BACKGROUND OF THE INVENTION

Most inorganic glasses at room temperature typically demonstrate values of electrical resistivity well in excess of 10⁸ ohm cm. However, it has long been recognized that a transparent membrane with high ionic conductivity would have considerable value. Thus, glasses with low electrical resistivities can have utility in electrochemical devices which demand high ionic conductivity.

The high ionic conductivity of copper and silver ions is well-known and glasses containing those ions have been formulated. Nevertheless, this prior research has not fully exploited the full capability of such glasses. For example, such glasses may exhibit an electrochromic phenomenon due to the electrochemical reduction of the copper and/or silver ions to the respective metal.

SUMMARY OF THE INVENTION

The present invention is founded in the discovery that glasses having compositions within the copper and/or silver-halide-phosphate system, wherein at least one halide is selected from the group of fluoride, bromide, chloride, and iodide, can be produced which have low softening points, high coefficients of thermal expansion, and which may have high conductivity and exhibit electrochromic behavior. The copper-containing glasses may also demonstrate thermochromic characteristics. Thus, such glasses have softening points below 400° C. and, in some instances, below 150° C. The coefficients of thermal expansion (25°-300° C.) are generally in excess of 180×10⁻⁷ /° C. and, hence, approximate those of certain metals. The glasses demonstrate electrical resistivities less than 10⁸ ohm cm. at room temperature (˜25° C.), preferably less than 10⁷ ohm cm, with certain compositions ranging down to less than 10³ ohm cm. Finally, the glasses can exhibit electrochromism based upon their high ionic conductivity.

Electrochromism is the change in color of an electrode due to the passage of electric current. Color is typically produced electrochemically via the reduction of an ion to the metal at the cathode or a change in oxidation state of a colorless ion to a colored ion at the cathode or anode. In the darkened state the charge is stored electrochemically, i.e., the system is the charged state of a battery. Fading of the color is promoted by shorting the electrodes or by reversing the d.c. field. If the electrodes are shorted, the driving force for fading is the internal EMF of the battery and, consequently, will typically be slow. However, if a reverse field of the same magnitude as that utilized to cause darkening is applied, then fading will be more rapid than darkening since the internal EMF of the system adds to the applied EMF.

FIGS. 1, 2, and 3 constitute ternary composition diagrams illustrating the areas of stable glasses which have been produced in the Cu₂ O-CuCl-P₂ O₅, the Cu₂ O-CuBr-P₂ O₅, and the Cu₂ O-CuI-P₂ O₅ system, respectively. Hence, in each diagram, transparent, stable glasses exhibiting a light yellow to amber color and demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm are depicted within the area delimited ABCD expressed in weight percent as calculated from the batch.

In FIG. 1, points A, B, C, and D have the approximate values recited below:

    A=0% Cu.sub.2 O, 70% CuCl, 30% P.sub.2 O.sub.5

    B=40% Cu.sub.2 O, 30% CuCl, 30% P.sub.2 O.sub.5

    C=20% Cu.sub.2 O, 30% CuCl, 50% P.sub.2 O.sub.5

    D=0% Cu.sub.2 O, 50% CuCl, 50% P.sub.2 O.sub.5

Glass compositions containing less than 30% CuCl were quite dark in color and showed electrical resistivities in excess of 10⁸ ohm cm. Compositions wherein the P₂ O₅ content exceeded 50% were poorly durable and also exhibited electrical resistivities greater than 10⁸ ohms. Compositions having less than 30% P₂ O₅ proved to be unstable with regard to devitrification. As can be seen, good stable glasses of high conductivity can be formed on the CuCl-P₂ O₅ binary.

In FIG. 2, points A, B, C, and D have the approximate concentrations reported below in weight percent:

    A=0% Cu.sub.2 O, 70% CuBr, 30% P.sub.2 O.sub.5

    B=50% Cu.sub.2 O, 20% CuBr, 30% P.sub.2 O.sub.5

    C=40% Cu.sub.2 O, 10% CuBr, 50% P.sub.2 O.sub.5

    D=0% Cu.sub.2 O, 50% CuBr, 50% P.sub.2 O.sub.5

Most of these glasses appeared to be somewhat lighter in color than the corresponding glasses containng CuCl. This phenomenon is believed to indicate less sensitivity to redox conditions in the melt. The same parameters were used to judge satisfactory glasses as were used with the CuCl-containing glasses. Acceptable glasses were found at higher Cu₂ O levels than were seen in the Cu₂ O-CuCl-P₂ O₅ system.

In the FIG. 3, points A, B, C, and D have the following approximate compositions in weight percent:

    A=0% Cu.sub.2 O, 70% CuI, 30% P.sub.2 O.sub.5

    B=50% Cu.sub.2 O, 20% CuI, 30% P.sub.2 O.sub.5

    C=40% Cu.sub.2 O, 10% CuI, 50% P.sub.2 O.sub.5

    D=0% Cu.sub.2 O, 50% CuI, 50% P.sub.2 O.sub.5

The composition ranges of suitable glasses were found to be essentially identical to those of the CuBr-containing glasses. Again, the same parameters were utilized to judge acceptable glasses as were used with the CuCl-containing glasses. In like manner to the CuBr and CuCl-containing glasses, good stable glasses demonstrating low electrical resistivities were found on the CuI-P₂ O₅ binary.

It will be appreciated, of course, that a combination of two or three halides, may be present in the glass compositions.

FIG. 4 illustrates that feature in that it constitutes a ternary composition diagram setting forth an area of stable glasses, expressed in terms of mole percent, demonstrating electrical resitivities at 25° C. of less than 10⁸ ohm cm which have been formed in the Cu₂ O-P₂ O₅ -X system wherein X is at least one halide selected from the group of Cl, Br, and I. Points A, B, and C have the following approximate compositions in mole percent:

    A=35% Cu.sub.2 O, 50% P.sub.2 O.sub.5, 15% X

    B=55% Cu.sub.2 O, 30% P.sub.2 O.sub.5, 15% X

    C=35% Cu.sub.2 O, 30% P.sub.2 O.sub.5, 35% X

The center of the scribed triangle is a point having the molecular formula Cu₂ O·P₂ O₅ ·1/2X, where X is one or more of the group Cl, Br, and I.

FIGS. 5, 6, 7, 8, 9, 10, and 11 represent ternary composition diagrams illustrating the areas of stable glasses demonstrating electrical resistivities at 25° C. of less than 10⁸ ohm cm which have been formed in the Ag₂ O-AgCl-P₂ O₅, the Ag₂ O-AgBr-P₂ O₅, the Ag₂ O-AgI-P₂ O₅, the Cu₂ O-P₂ O₅ -F, the Cu₂ O-P₂ O₅ -Cl/F, the Cu₂ O-P₂ O₅ -Br/F, and the Cu₂ O-P₂ O₅ -I/F system, respectively.

In FIG. 5, points A, B, C, and D have the approximate values set out below in weight percent:

    A=42% Ag.sub.2 O, 46% AgCl, 12% P.sub.2 O.sub.5

    B=73% Ag.sub.2 O, 3% AgCl, 24% P.sub.2 O.sub.5

    C=52% Ag.sub.2 O, 3% AgCl, 45% P.sub.2 O.sub.5

    D=30% Ag.sub.2 O, 46% AgCl, 24% P.sub.2 O.sub.5

Although glasses free from chloride can be prepared which are ionic conducting and electrochromic, the durability and electrical conductivity thereof are significantly improved through the addition of chloride to the composition. Accordingly, a finite amount of chloride will be incorporated into the glass composition effective to improve those properties. In general, chloride in an amount of at least 1% will be included in the composition (1% Cl≡3% AgCl) with at least 5% being preferred.

Glasses within the area ABCD vary in color from colorless to a pale yellow, are quite fluid, can exhibit electrochromic behavior, and soften at temperatures between about 200°-400° C. Rather rapid cooling of the individual melts was necessitated since several thereof tended to devitrify upon slow cooling. Compositions containing excessive amounts of P₂ O₅ formed glasses which were poorly durable and demonstrated electrical resistivities greater than 10⁸ ohm cm. The presence of Ag₂ O and/or AgCl in high quantities reduces the stability of the glass against devitrification.

In FIG. 6, points A, B, C, and D have the approximate values reported below in weight percent:

    A=36% Ag.sub.2 O, 56% AgBr, 8% P.sub.2 O.sub.5 ps

    B=74% Ag.sub.2 O, 2% AgBr, 24% P.sub.2 O.sub.5

    C=54% Ag.sub.2 O, 2% AgBr, 44% P.sub.2 O.sub.5

    D=24% Ag.sub.2 O, 56% AgBr, 20% P.sub.2 O.sub.5

Similarly to the AgCl-containing glasses discussed above, bromide is incorporated into the composition in an effective amount, usually at least about 1% (1% Br≡2% AgBr) with a minimum of 5% being preferred, to improve the durability and electrical conductivity of the glass. The glasses within area ABCD were pale yellow in color and, like the AgCl-containing glasses above, can exhibit electrochromic behavior, are quite fluid, and soften at temperatures below about 400° C. The same parameters were used to judge acceptable glasses as were used with the AgCl-containing glasses. Higher Ag₂ O levels were found operable than were seen in the Ag₂ O-AgCl-P₂ O₅ system glasses.

In FIG. 7, points A, B, C, D, and E have the following approximate compositions in weight percent:

    A=16% Ag.sub.2 O, 70% AgI, 14% P.sub.2 O.sub.5

    B=35% Ag.sub.2 O, 60% AgI, 5% P.sub.2 O.sub.5

    C=74.5% Ag.sub.2 O, 1.5% AgI, 24% P.sub.2 O.sub.5

    D=53.5% Ag.sub.2 O, 1.5% AgI, 45% P.sub.2 O.sub.5

    E=16% Ag.sub.2 O, 40% AgI, 44% P.sub.2 O.sub.5

In like manner to the AgCl-containing glasses, iodide is included in the composition in an effective amount, typically at least about 1% (1% I≡1.5% AgI) with at least 5% being preferred, to enchance the durability and electrical conductivity of the glass. The glasses within area ABCDE were a darker yellow than the AgBr-containing compositions. Glasses still higher in AgI content were found to exhibit good ionic conductivity but were very dark brown in color and/or darkened in visible light. The same parameters were employed to judge satisfactory glasses as were used with the AgCl-containing glasses. Concentrations of AgI higher than either AgCl or AgBr are operable in the invention.

In FIG. 8, points A, B, C, D, and E have the following approximate compositions in weight percent:

    A=90% P.sub.2 O.sub.5, 9% Cu.sub.2 O, and 1% F

    B=69% P.sub.2 O.sub.5, 30% Cu.sub.2 O, and 1% F

    C=50% P.sub.2 O.sub.5, 30% Cu.sub.2 O, and 20% F

    D=50% P.sub.2 O.sub.5, 15% Cu.sub.2 O, and 35% F

    E=62% P.sub.2 O.sub.5, 3% Cu.sub.2 O, and 35% F

    F=90% P.sub.2 O.sub.5, 3% Cu.sub.2 O, and 7% F

Glass compositions containing more than 90% P₂ O₅ were so poorly durable as to be essentially useless from a practical point of view, whereas when less than 50% P₂ O₅ was utilized the glasses were difficult to melt and/or unstable with respect to devitrification. The presence of fluoride improves the electrical conductivity of the simple Cu₂ O-P₂ O₅ glasses. However, the glasses exhibited a very dark green color.

It will be recognized that a combination of two or three halides may be present in the glass compositions. This is evidenced in FIGS. 9, 10, and 11.

FIG. 9 sets forth the operable composition area of the system P₂ O₅ -Cu₂ O-F/Cl in weight percent wherein the total F/Cl represents the sum of equal molar amounts of F and Cl. In FIG. 8, points A, B, C, D, E, and F have the following approximate compositions in weight percent:

    A=40% P.sub.2 O.sub.5, 55% Cu.sub.2 O, 5% F/Cl

    B=20% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 5% F/Cl

    C=15% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 10% F/Cl

    D=15% P.sub.2 O.sub.5, 45% Cu.sub.2 O, 40% F/Cl

    E=25% P.sub.2 O.sub.5, 35% Cu.sub.2 O, 40% F/Cl

    F=40% P.sub.2 O.sub.5, 35% Cu.sub.2 O, 25% F/Cl

Less than about 15% P₂ O₅ hazards glass instability. The glasses demonstrated colors ranging from light yellow, through amber, to a red amber appearance. The mixture of halide displays a very positive effect in lowering electrical resistivity when compared with any one alone. Thus, resistivities of less than 10⁴ ohm cm have been measured at room temperature.

FIG. 10 reports the operable composition area of the system P₂ O₅ -Cu₂ O-F/Br in weight percent. In like manner to F/Cl in FIG. 9, the expression F/Br represents the sum of equal molar amounts of F and Br. Points A, B, C, D, E, and F have the following approximate compositions in weight percent:

    A=50% P.sub.2 O.sub.5, 45% Cu.sub.2 O, 5% F/Br

    B=20% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 5% F/Br

    C=15% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 10% F/Br

    D=15% P.sub.2 O.sub.5, 45% Cu.sub.2 O, 40% F/Br

    E=40% P.sub.2 O.sub.5, 20% Cu.sub.2 O, 40% F/Br

    F=50% P.sub.2 O.sub.5, 20% Cu.sub.2 O, 30% F/Br

As was the case with the F/Cl compositions, glasses containing less than about 15% P₂ O₅ are unstable with regard to devitrification. Also, the glasses exhibited coloration ranging from light yellow to red amber and electrical resistivities approaching 10³ ohm cm have been measured at room temperature.

FIG. 11 diagrams the operable composition area of the system P₂ O₅ -Cu₂ O-F/I in weight percent. Similarly to F/Cl in FIG. 9 and F/Br in FIG. 10, the term F/I represents the sum of equal molar amounts of F and I. Points A, B, C, D, E, and F have the following approximate compositions in weight percent:

    A=50% P.sub.2 O.sub.5, 45% Cu.sub.2 O, 5% F/I

    B=20% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 5% F/I

    C=15% P.sub.2 O.sub.5, 75% Cu.sub.2 O, 10% F/I

    D=15% P.sub.2 O.sub.5, 40% Cu.sub.2 O, 45% F/I

    E=35% P.sub.2 O.sub.5, 20% Cu.sub.2 O, 45% F/I

    F=50% P.sub.2 O.sub.5, 20% Cu.sub.2 O, 30% F/I

Yet again, at least about 15% P₂ O₅ is necessary to provide against glass instability. The glasses were generally somewhat darker than the Cl and Br containing glasses, the colors varying from a light amber to dark brown. Also, the electrical resistivities measured at room temperature were not quite as low as the Cl and Br containing glasses. However, the values were generally less than where only one halide was incorporated into the glass compositions.

Furthermore, substitutions in part of copper for silver and vice versa can be made in each of the above groups of compositions outlined in FIGS. 1-11.

The electrochromic systems which appear to be of great present interest utilize a solid electrolyte and darken by the electrochemical reduction of an ion to the metal at the cathode or produce a transition metal ion that is colored in the reduced state. Those systems based upon the electrochemical reduction of an ion to the corresponding metal are more efficient because of the large optical absorption coefficient of metals.

In order to measure the properties of an electrochromic system, two transparent electrodes were placed on opposite sides of the electrochemical cell. This could be accomplished via R.F. sputtering of Sn-In₂ O₃ or Sb-SnO₂ films. However, a more rapid and convenient system was devised wherein the electrochemical cell was sandwiched between two pieces of glass coated with Sb-SnO₂ films by chemical vapor deposition. This process has been described in such literature as U.S. Pat. Nos. 2,564,707 and 3,331,702. Such a system limits the capability of electrochromic measurements to solid electrolytes having low softening points but that is precisely the type of materials resulting from the present invention.

Optical transmission measurements are customarily made with a photodiode using white light. However, the visible spectrum of each system was studied spectrophotometrically.

The resistivities reported for solid ionic conductors are normally measured with a.c. current to preclude the occurrence of polarization. For an electrochromic system, however, darkening takes place via an electrochemical reaction, i.e., in the region of polarization. A typical current-voltage relationship existing for an electrochemical reaction is set forth in FIG. 12.

In region A of that FIGURE, little current is passed through the cell and no irreversible reactions take place. In region B, electrochemical oxidation and reduction commence. Region C denotes the electrochemical reactions taking place at the maximum rate for the system. Hence, it is in region C where the electrochromic system should be operated for maximum speed. Unfortunately, the current in region C is too great for the Ag₂ O and/or Cu₂ O-halide-P₂ O₅ system, thereby leading to degradation. Consequently, the glasses of the instant invention require operation in region B.

By the very nature of the system, i.e., alternating from the discharged to the charged and back to the discharged state of a battery, the resistivity of the cell is voltage dependent. Therefore, the system is best characterized by the current-voltage representation rather than by a single resistivity value.

The darkening due to the electrochemical reduction of Ag⁺ Ag° is fundamentally a very efficient reaction because of the large absorption coefficient of copper and silver. The transmission of an electrochromic system is represented by ##EQU1## where k is the absorption coefficient of the absorbing layer of thickness d at a wavelength λ.

Utilizing silver as the example, λ=5600A and k=3.75. In this manner, Equation 1 becomes

    1n(T/T.sub.o)=0.0084d                                      (Equation 2)

where d is the thickness of silver in A. If the current efficiency of the system is assumed to be 100%, then the transmission can be calculated in terms of the amount of charge passed through the cell. Based upon that assumption, Equation 1 becomes

    1n(T/T.sub.o)=89.6Q                                        (Equation 3)

where Q is delineated in coulombs. To achieve a transmission of 50%, less than 0.008 coulomb/cm² is required. This value corresponds to 8 seconds at a current of 1 ma/cm². FIG. 13 depicts the transmission-time relationship calculated for the silver system at a constant current of 1 ma/cm². Whereas Equations 1-3 were calculated at a wavelength of 5600 A, actual spectra obtained of electrochromic cells of Ag-containing glasses in the darkened state manifest that the transmission is generally uniform across the visible spectrum within about 5%.

To reduce the transmission of the Ag-containing system to 50% requires 8.65 μg of Ag/cm². This amount of Ag is equivalent to depleting silver from the glass to a depth of about 235 A. It is conjectured, however, that the Ag comes from a depth of several thousand angstroms within the glass and not just from an interface layer. Even reducing the transmission to 25% demands only about 17 μg of Ag/cm². This quantity of silver is less than 2.4% of that present in a 2 micron film of Ag₂ O·AgCl.·P₂ O₅ glass. The thickness of the typical laminate structure used for measurements is greater than 1000 microns.

An electrochemical cell utilizing a cuprous halophosphate glass demonstrates a markedly different mechanism for electrochromic behavior. FIG. 14 illustrates the darkening in transmission exhibited by a glass consisting, by weight, of 40% P₂ O₅, 20% Cu₂ O, and 40% CuI when a field of one volt is applied thereacross. With this glass the darkening occurs at the anode of the device instead of the cathode, thereby indicating that the electrochemical reaction is the result of an oxidation rather than a reduction mechanism. The color of the darkened film is black, the appearance thereof being similar to that typical of the mixed valency copper oxide black used as optically absorbing coatings.

Although the complete details of the mechanism are not known, the summation of the anode reaction is believed to be:

    Cu.sup.+ →Cu.sup.+2 +e.sup.-

This produces a region of glass at the anode where both cupric and cuprous ions exist, in contrast to the original glass where substantially all the copper is present as cuprous ions.

It is well recognized that a strongly allowed optical transition exists between the two valence states of copper leading to the development of copper oxide black, the intensity thereof being proportional to the product of the concentrations of the cupric and cuprous ion species. Consequently, when an electric field of sufficient magnitude is applied to a cuprous halophosphate glass, an optically absorbing film is produced at the anode via a mixed valency mechanism. Measurements on such glasses as that described above, viz., 40% P₂ O₅, 20% Cu₂ O, and 40% CuI, and 30% P₂ O₅, 40% Cu₂ O, and 30% CuBr have demonstrated that the darkening mechanism is electrically efficient, requiring on the order of 0.01-0.05 coulombs/cm² for significant darkening. FIG. 14 shows a darkening of about 50% after the application of one volt for about four minutes. That glass will fade back to its original transmission by simply removing the applied field. Thus, the glass will assume its original transmission at room temperature without requiring the application of a reverse field thereto. This fading can be expedited by exposure to slightly elevated temperatures.

It is believed that this same mechanism of mixed valency darkening is responsible for an additional phenomenon observed in the Cu₂ O-P₂ O₅ -CuX glasses encompassed within the compositions defined in FIGS. 1-3, viz., thermochromic behavior. For example, a glass having a composition of 30% P₂ O₅, 40% Cu₂ O, and 30% CuBr will change its optical transmission by 50% when it is subjected to a temperature change from 70° C. to 25° C. The glass is more absorbing, i.e., it is darker in color, at the higher temperature. It will be appreciated that under these conditions the oxidation of cuprous ions is effected thermally and occurs throughout the glass rather than solely at an interface, as is the case with the electrochromic mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-CuCl-P₂ O₅ system.

FIG. 2 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-CuBr-P₂ O₅ system.

FIG. 3 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-CuI-P₂ O₅ system.

FIG. 4 constitutes a ternary composition diagram illustrating an area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-P₂ O₅ -X field, expressed in mole percent, wherein X is at least one halide selected from the group of Cl, Br, and I.

FIG. 5 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Ag₂ O-AgCl-P₂ O₅ system.

FIG. 6 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Ag₂ O-AgBr-P₂ O₅ system. FIG. 7 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Ag₂ O-AgI-P₂ O₅ system.

FIG. 8 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-P₂ O₅ -F system.

FIG. 9 constitutes a tenary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-P₂ O₅ -F/C1 system.

FIG. 10 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-P₂ O₅ -F/Br system.

FIG. 11 constitutes a ternary composition diagram illustrating the area of stable glasses demonstrating an electrical resistivity at 25° C. of less than 10⁸ ohm cm produced in the Cu₂ O-P₂ O₅ -F/I system.

FIG. 12 sets forth a typical current-voltage relationship existing for an electrochemical reaction.

FIG. 13 represents the transmission-time relationship calculated for the silver system at a constant current of 1 ma/cm².

FIG. 14 graphically depicts the typical relative transmission: time relationship which a glass having a composition in the P₂ O₅ -Cu₂ O-CuI field exhibits when subjected to a constant applied potential of one volt. The optical transmission is plotted in terms of relative units.

DETAILED DESCRIPTION OF THE INVENTION

Table I recites several compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses coming within the quadrangle ABCD reported in FIG. 1. Table IA records the batch ingredients utilized, expressed in parts by weight.

Melting of the batch ingredients was conducted in covered crucibles, generally VYCOR® brand 96 percent silica crucibles, marketed by Corning Glass Works, Corning, New York, or glazed porcelain, at temperatures between about 70°-1100° C. for about 10-15 minutes. This melting practice, coupled with the character of the batch ingredients, provided a sufficiently reducing environment to insure that the copper was present in the glass in the cuprous state. The time for melting was kept short to avoid loss through volatilization. The molten batches were very fluid, even when cooled to 300°-400° C. The melts were poured onto a steel plate and a part thereof pressed to a thin plate having a thickness of 1 mm or less.

Table IB reports visual observations made on the glass specimens and electrical resistivity measurements made at room temperature by contacting the glass with probes from a Simpson 260 volt ohm milliammeter marketed by Simpson Electric Company, Elgin, Ill.

                  TABLE I                                                          ______________________________________                                         Example No. P.sub.2 O.sub.5                                                                           Cu.sub.2 O CuCl                                         ______________________________________                                         1           35         32.5       32.5                                         2           30         35         35                                           3           40         30         30                                           4           40         20         40                                           5           40         10         50                                           6           40         5          55                                           7           40         --         60                                           8           35         --         65                                           ______________________________________                                    

                  TABLE IA                                                         ______________________________________                                         Example No.                                                                               NH.sub.4 H.sub.2 PO.sub.4                                                                  Cu.sub.2 O CuCl                                         ______________________________________                                         1          5.67        3.25       3.25                                         2          4.86        3.5        3.5                                          3          6.48        3          3                                            4          6.48        2          4                                            5          6.48        1          5                                            6          6.48        0.5        5.6                                          7          6.48        --         6                                            8          5.67        --         6.5                                          ______________________________________                                    

                  TABLE IB                                                         ______________________________________                                                                      Surface                                                                        Resistance                                        Example No.                                                                               Appearance        (ohms × 10.sup.4)                           ______________________________________                                         1          Clear if quenched, crystal-                                                                      300                                                          line if not                                                         2          Clear dark amber glass                                                                           500                                               3          Black glass       1000                                              4          Clear amber glass 400                                               5          "                 1000                                              6          "                 1000                                              7          "                 2000                                              8          "                 40                                                ______________________________________                                    

Table II lists several compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses coming within the quadrangle ABCD reported in FIG. 2. Table IIA reports the batch ingredients used, expressed in parts by weight.

Melting of the batch ingredients and forming of the molten batches were undertaken in like manner to the exemplary compositions of Table I. Table IIB recites visual observations noted on the glass samples along with electrical resistivity determinations made at room temperature utilizing a Simpson ohm-meter.

                  TABLE II                                                         ______________________________________                                         Example No.                                                                               P.sub.2 O.sub.5                                                                           Cu.sub.2 O CuBr                                          ______________________________________                                          9         40         30         30                                            10         40         20         40                                            11         40           17.5       17.5                                        12         50         30         20                                            13         40         40         20                                            14         30         --         70                                            15         30         30         40                                            16         30         50         20                                            17         40         --         60                                            18         35         25         40                                            19         45         35         20                                            20         45         30         25                                            21         45         25         30                                            22         45         20         35                                            23         40         15         45                                            24         35         --         65                                            ______________________________________                                    

                  TABLE IIA                                                        ______________________________________                                         Example No.                                                                             NH.sub.4 H.sub.2 PO.sub.4                                                                 Cu.sub.2 O                                                                              CuBr   H.sub.3 PO.sub.4 (85%)                     ______________________________________                                          9       6.48       3        3      --                                         10       --         2        4      6.52                                       11       7.29       1.75     3.75   --                                         12       8.10       3        2      --                                         13       6.48       4        2      --                                         14       4.86       --       2                                                 15       4.86       3        4      --                                         16       4.86       5        2      --                                         17       6.48       --       6      --                                         18       5.67       2.5      4      --                                         19       7.29       3.5      2      --                                         20       7.29       3        2.5    --                                         21       7.29       2.5      3      --                                         22       7.29       2        3.5    --                                         23       6.48       1.5      4.5    --                                         24       5.67       --       6.5    --                                         ______________________________________                                    

                  TABLE IIB                                                        ______________________________________                                                                      Resistivity                                       Example No.                                                                             Appearance          (ohms × 10.sup.4)                           ______________________________________                                          9       Clear amber glass   30                                                10       Clear light amber glass                                                                            70                                                11       Clear amber glass   2000                                              12       "                   --                                                13       "                   200                                               14       "                   70                                                15       Clear dark amber if quenched,                                                                      10                                                         crystalline if not                                                    16       Clear dark amber if quenched,                                                                      500                                                        crystalline if not                                                    17       Clear dark amber glass                                                                             200                                               18       Clear light amber glass                                                                            10                                                19       Clear amber glass   1000                                              20       "                   500                                               21       "                   400                                               22       "                   1000                                              23       "                   100                                               24       "                   70                                                ______________________________________                                    

Table III records several compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses encompassed within the quadrangle ABCD outlined in FIG. 3. Table IIIA lists the batch ingredients utilized, expressed in parts by weight.

Melting of the batch ingredients and forming of the molten batches were conducted in similar fashion to the exemplary compositions of Table I. Table IIIB reports visual observations made on the glass samples along with electrical resistivity measurements determined via a Simpson ohm-meter.

                  TABLE III                                                        ______________________________________                                         Example No. P.sub.2 O.sub.5                                                                           Cu.sub.2 O CuI                                          ______________________________________                                         25          40         30         30                                           26          30         --         70                                           27          40         --         60                                           28          50         --         50                                           29          40          5         55                                           30          40         10         50                                           31          40         15         45                                           32          40         20         40                                           ______________________________________                                    

                  TABLE IIIA                                                       ______________________________________                                         Example No.                                                                               NH.sub.4 H.sub.2 PO.sub.4                                                                   Cu.sub.2 O CuI                                         ______________________________________                                         25         6.48         3          3                                           26         4.86         --         7                                           27         6.48         --         6                                           28         8.10         --         5                                           29         6.48         0.5        5.5                                         30         6.48         1          5                                           31         6.48         1.5        4.5                                         32         6.48         2          4                                           ______________________________________                                    

                  TABLE IIIB                                                       ______________________________________                                                                      Resistivity                                       Example No.                                                                              Appearance         (ohms × 10.sup.4)                           ______________________________________                                         25        Clear amber glass  70                                                26        Light amber clear if quenched,                                                                    2                                                           crystalline if not                                                   27        Clear amber glass  150                                               28        Dark amber glass   --                                                29        Clear amber glass  300                                               30        "                  50                                                31        Clear light amber glass                                                                           50                                                32        "                  25                                                ______________________________________                                    

Table IV reports two compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses consisting of more than three components. Table IVA recites the batch constituents employed, expressed in parts by weight. The glasses are stable and exhibit high electrical conductivity.

Melting of the batch ingredients and forming of the molten batches were carried out in accordance with the procedure outlined above for the exemplary compositions of Table I. Table IVB notes visual observations made on the glass specimens along with electrical resistivity measurements made with a Simpson ohm-meter.

                  TABLE IV                                                         ______________________________________                                         Example No.                                                                              P.sub.2 O.sub.5                                                                         Cu.sub.2 O                                                                               CuO    CuBr                                       ______________________________________                                         33        40       15         5     40                                         34        30       15        15     40                                         ______________________________________                                    

                  TABLE IVA                                                        ______________________________________                                         Example No.                                                                              Cu.sub.2 O                                                                              CuO      CuBr    NH.sub.4 H.sub.2 PO.sub.4                  ______________________________________                                         33        1.5      0.5      4       6.48                                       34        1.5      1.5      4       4.86                                       ______________________________________                                    

                  TABLE IVB                                                        ______________________________________                                                                      Resistivity                                       Example No.                                                                              Appearance         (ohms × 10.sup.4)                           ______________________________________                                         33        Clear amber glass  70                                                34        Clear dark amber if quenched,                                                                      5                                                          crystalline if not                                                   ______________________________________                                    

Chemical analyses were performed upon nine of the above glasses to determine the effect of volatilization. The analyses were reported in terms of Cu₂ O, P₂ O₅, and halide. Table V compares the theoretical compositions as calculated from the batch with the analyzed values. The compositions are adjusted to 100% by weight.

                                      TABLE V                                      __________________________________________________________________________     Example                                                                             Theoretical      Analyzed                                                 No.  P.sub.2 O.sub.5                                                                   Cu.sub.2 O                                                                         Cl Br  I  P.sub.2 O.sub.5                                                                   Cu.sub.2 O                                                                         Cl Br  I                                          __________________________________________________________________________      4   38.8                                                                              47.4                                                                               13.8                                                                              --  -- 42.8                                                                              51.7                                                                               5.5                                                                               --  --                                          5   38.5                                                                              44.5                                                                               17.0                                                                              --  -- 49.5                                                                              46.1                                                                               4.4                                                                               --  --                                          8   33.3                                                                              44.8                                                                               21.9                                                                              --  -- 41.1                                                                              52.8                                                                               6.1                                                                               --  --                                         14   28.7                                                                              41.9                                                                               -- 29.4                                                                               -- 34.7                                                                              42.5                                                                               -- 22.8                                                                               --                                         17   38.5                                                                              36.2                                                                               -- 25.3                                                                               -- 50.7                                                                              38.9                                                                               -- 10.4                                                                               --                                         18   34.1                                                                              48.8                                                                               -- 17.1                                                                               -- 33.5                                                                              47.8                                                                               -- 18.7                                                                               --                                         26   29.2                                                                              25.5                                                                               -- --  45.3                                                                              35.3                                                                              38.1                                                                               -- --  26.6                                       31   39.3                                                                              31.3                                                                               -- --  29.4                                                                              45.2                                                                              37.1                                                                               -- --  17.7                                       32   39.4                                                                              34.4                                                                               -- --  26.2                                                                              40.1                                                                              38.3                                                                               ----                                                                              21.6                                           __________________________________________________________________________

One important finding resulting from the chemical analysis of the copper-containing glasses is that the analyzed concentration of cuprous copper is essentially equivalent to the total copper concentration. The level of Cu^(o) was too low to analyze but this circumstance does not rule out the presence of colloidal copper in trace amounts to act as a colorant. The primary loss through volatilization was halide with the chloride loss being greater than that of bromide or iodide.

Table VI recites the analyzed values of the Examples listed in Table V approximated in terms of mole percent.

                  TABLE VI                                                         ______________________________________                                         Example No.                                                                               P.sub.2 O.sub.5                                                                        Cu.sub.2 O                                                                              Cl    Br    I                                      ______________________________________                                          4         30.4    44.6     19.1  --     --                                     5         44.0    40.6     15.6  --    --                                      8         35.0    44.3     20.7  --    --                                     14         29.6    36.0     --    34.5  --                                     17         47.2    36.0     --    17.2  --                                     18         29.3    41.7     --    29.2  --                                     26         34.2    36.7     --    --    34.5                                   31         44.4    36.7     --    --    19.6                                   32         39.2    37.2     --    --    23.6                                   ______________________________________                                    

Table VII records several compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses having electrical resistivities at room temperature less than about 10⁸ ohm cm coming within the quadrangle ABCD cited in FIG. 5. The batch materials consisted of AG₂ O, AgC, and H₃ PO₄ (85% by weight).

The melting of the batch constituents and the forming of the resulting melt were undertaken in like manner to the description above with respect to the compositions of Table I. Table VIIA records visual observations noted on the glass specimens and electrical resistivity measurements conducted at room temperature via the probes of a Simpson ohm-meter.

                  TABLE VII                                                        ______________________________________                                         Example No. P.sub.2 O.sub.5                                                                           Ag.sub.2 O AgCl                                         ______________________________________                                         33          34.2       55.8       10                                           34          32.3       52.7       15                                           35          30.4       49.6       20                                           36          26.6       43.4       30                                           37          24.7       40.3       35                                           38          22.8       37.2       40                                           39          25         45         30                                           40          22.5       47.5       30                                           41          20         50         30                                           42          17.5       52.5       30                                           43          15         55         30                                           44          12.5       57.5       30                                           45          25         10         65                                           46          25         53         22                                           47          25         50         25                                           48          15         45         40                                           49          20         40         40                                           ______________________________________                                    

                  TABLE VIIA                                                       ______________________________________                                                                      Resistivity                                       Example No.                                                                             Appearance          (ohms × 10.sup.4)                           ______________________________________                                         33       Pale yellow clear if                                                           quenched, crystalline if not                                                                       2000                                              34       Pale yellow clear if                                                           quenched, crystalline if not                                                                       1000                                              35       Pale yellow clear if                                                           quenched, crystalline if not                                                                       500                                               36       Pale yellow clear glass                                                                            --                                                37       Clear glass if quenched,                                                       crystalline if not                                                    38       Clear glass if quenched,                                                       crystalline if not  500                                               39       Clear pale yellow if                                                                               300                                                        quenched, hazy if not                                                 40       Clear pale yellow if                                                           quenched, hazy if not                                                                              300                                               41       Clear yellow glass  200                                               42       Clear amber glass   150                                               43       Clear yellow if quenched,                                                                           70                                                        crystalline if not                                                    44       Clear yellow if quenched,                                                      crystalline if not  150                                               45       Clear if quenched, hazy                                                                            --                                                         crystalline if not                                                    46       Clear if quenched, hazy                                                                            500                                                        if not, yellow                                                        47       Clear if quenched, hazy                                                        if not, yellow      500                                               48       Clear if quenched,   40                                                        crystaline if not, yellow                                             49       Clear if quenched,                                                             crystalline if not, yellow                                                                          30                                               ______________________________________                                    

Table VIII reports several compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses exhibiting electrical resistivities determined at room temperature of less than about 10⁸ ohm cm within the quadrangle ABCD represented in FIG. 6. Thebatch materials consisted of Ag₂ O, AgBr, and 85% H₃ PO₄.

The melting of the batch components and the forming of the resulting molten mass were conducted in accordance with the description outlined above with regard to the compositions of Table I. Table VIIIA lists visual observations noted on the glass samples and electrical resistivity measurements made at room temperature utilizing a Simpson ohm-meter.

                  TABLE VIII                                                       ______________________________________                                         Example No. P.sub.2 O.sub.5                                                                           Ag.sub.2 O AgBr                                         ______________________________________                                         50          23         67         10                                           51          20.4       59.6       20                                           52          17.8       52.2       30                                           53          12.8       37.2       50                                           54          17         53         30                                           55          16         54         30                                           56          15         55         30                                           57          14         56         30                                           58          22         68         10                                           59          12         38         50                                           60          11         39         50                                           61          10         40         50                                           62          14         45         40                                           63          20         40         40                                           ______________________________________                                    

                  TABLE VIIIA                                                      ______________________________________                                                                      Resistivity                                       Example No.                                                                             Appearance          (ohms × 10.sup.4)                           ______________________________________                                         50       Clear light yellow glass                                                                           500                                               51       Clear yellow glass  200                                               52       "                   100                                               53       "                   15                                                54       "                   70                                                55       Clear yellow is quenched,                                                                          50                                                         crystalline if not                                                    56       Clear yellow is quenched,                                                                          50                                                         hazy if not                                                           57       Clear yellow if quenched,                                                                          200                                                        crystalline if not                                                    58       Clear yellow if quenched,                                                      crystalline if not  500                                               59       Clear brown glass   20                                                60       Clear yellow glass  20                                                61       Clear yellow if quenched,                                                                          20                                                         crystalline if not                                                    62       Clear yellow glass  50                                                63       "                   50                                                ______________________________________                                    

Table IX lists a number of compositions, expressed in weight percent on the oxide basis as calculated from the batch, of stable glasses having electrical resistivities measured at room temperature of less than about 10⁸ ohm cm within the area ABCDE represented in FIG. 7. The batch materials consisted of Ag₂ O, AgI, and 85% H₃ PO₄.

The melting of the batch constituents and the forming of the melts were undertaken in the same way as that described above with respect to the compositions of Table I. Table IXA reports the visual appearance observed on the glass specimens and electrical resistivity determinations conducted at room temperature employing a Simpson ohm-meter.

                  TABLE IX                                                         ______________________________________                                         Example No. P.sub.2 O.sub.5                                                                           Ag.sub.2 O AgI                                          ______________________________________                                         64          20         40         40                                           65          15         25         60                                           66          15         35         50                                           67          18         32         50                                           68          26         44         30                                           69          15         55         30                                           70          24         26         50                                           71          14         45         40                                           72          25         35         40                                           73          15         20         60                                           74          10         30         60                                           75          20         20         60                                           76          20         60         20                                           77          10         50         40                                           78          30         20         50                                           79          10         40         50                                           80          35         25         40                                           81          35         35         30                                           82          45         25         30                                           ______________________________________                                    

                  TABLE IXA                                                        ______________________________________                                                                      Resistivity                                       Example No.                                                                              Appearance         (ohms × 10.sup.4)                           ______________________________________                                         64        Clear orange glass 10                                                65        Clear yellow glass 0.02                                              66        Clear yellow if quenched,                                                                         0.1                                                         crystalline if not                                                   67        Clear light amber glass                                                                           2                                                 68        Clear yellow glass if quenched,                                                                   70                                                          hazy if not                                                          69        Clear amber glass  30                                                70        Clear yellow glass 0.1                                               71        Clear yellow glass if quenched,                                                                   0.4                                                         translucent if not                                                   72        Clear yellow glass --                                                73        Clear yellow glass if quenched,                                                                   0.01                                                        crystalline if not                                                   74        Clear orange glass 0.07                                              75        Clear orange glass if quenched,                                                                   0.02                                                        crystalline if not                                                   76        Clear orange glass if quenched,                                                                   150                                                         translucent if not                                                   77        Clear yellow glass if quenched,                                                                   0.05                                                        crystalline if not                                                   78        Clear dark amber if quenched,                                                                     10                                                          crystalline if not                                                   79        Clear orange glass 5                                                 80        Clear light yellow if quenched,                                                                   10                                                          hazy if not                                                          81        Clear yellow glass 200                                               82        Pale yellow glass if quenched,                                                                    200                                                         translucent if not                                                   ______________________________________                                    

Table X records several stable glasses in the Ag₂ O-mixed halide-P₂ O₅ systems where the batches were precipitated in the known manner from aqueous solutions of NaPO₃, AgNO₃, NaCl, NaBr, and NaI, dried, and then melted to a glass. The values reported are expressed in weight percent on the oxide basis as calculated from the batch. Table XA recites the batch materials in terms of parts by weight.

The melting of the batch ingredients and the forming of the molten batches were carried out in the same fashion as described above with respect to the compositions of Table I. Table XB reports the visual appearance observed and the electrical resistivities measured at room temperature with a Simpson ohm-meter.

                  TABLE X                                                          ______________________________________                                         Example No.                                                                             P.sub.2 O.sub.5                                                                        Ag.sub.2 O                                                                              AgCl   AgBr   AgI                                    ______________________________________                                         84       30.4    49.6     8.4    --     11.6                                   84       12      58       12.6   --     17.4                                   85       16      54       12.6   --     17.4                                   86       27.6    42.4     --     10     20                                     87       28.5    46.5     15     10     --                                     88       28.5    46.5     15     --     10                                     89       28.5    46.5     15     5      5                                      90       26.6    43.4     20     5      5                                      ______________________________________                                    

                  TABLE XA                                                         ______________________________________                                         Example No.                                                                             NaPO.sub.3                                                                             AgNO.sub.3                                                                              NaCl   NaBr   NaI                                    ______________________________________                                         83       21.85   45.60    1.80   --     3.60                                   84       6.96    45.87    2.02   --     4.45                                   85       9.28    42.71    2.02   --     4.45                                   86       4.00    8.57     --     0.55   1.28                                   87       10.88   13.69    0.62   0.55   --                                     88       10.88   13.51    0.62   --     0.64                                   89       10.88   13.60    0.62   0.28   0.32                                   90       10.15   13.46    0.82   0.28   0.32                                   ______________________________________                                    

                  TABLE XB                                                         ______________________________________                                                                   Resistivity                                          Example No.  Appearance   (ohms × 10.sup.4)                              ______________________________________                                         83           Clear glass  --                                                   84             "          --                                                   85             "          --                                                   86           Hazy yellow glass                                                                            100                                                 87           Clear if quenched,                                                                          1000                                                              crystalline if not                                                88           Clear if quenched,                                                             crystalline if not                                                                          1000                                                 89           Clear if quenched,                                                             crystalline if not                                                                          1000                                                 90           Clear if quenched,                                                             crystaline if not                                                                            500                                                 ______________________________________                                    

Table XI lists several exemplary compositions, expressed in mole percent on the oxide basis as calculated from the batch, wherein various additives were included in the base P₂ O₅ -Ag₂ O-X system, wherein X is selected from the group of Cl, Br, and I. The glasses were prepared in the following manner. Appropriate amounts of AgNO₃ and H₃ PO₄ were blended together and the mixture heated to about 200° C., at which time the AgNO₃ melted and a clear, colorless, homogeneous solution resulted. Upon further heating, viz., up to 500° C., water and nitrogen oxide fumes were evolved. The resultant melt was heated to about 700° C. and held at that temperature for about one hour to insure removal of water and the nitrogen oxides. A AgPO₃ glass was formed by pouring the melt onto a stainless steel block. The glass was annealed at 160° C.

An appropriate amount of a silver halide was then mixed with a comminuted sample of th AgPO₃ glass and the mixture fused at about 450° C. The additive materials were then dissolved in the molten mass. To prepare glasses containing BaO, ZnO, La₂ O₃, desired amounts of the hydrated forms of the nitrates of those oxides were added slowly to the molten Ag₂ O-P₂ O₅ -X. A vigorous reaction ensued with oxides of nitrogen as well as water being emitted. The addition of such constituents as B₂ O₃, Al₂ O₃, and LiF can be made by simply incorporating them in that form into the molten Ag₂ O-P₂ O₅ -X. The resultant Ag₂ O-P₂ O₅ -X additive oxide glasses are generally yellow in color.

                  TABLE XI                                                         ______________________________________                                         Example No.                                                                             Ag.sub.2 O                                                                              P.sub.2 O.sub.5                                                                         AgCl   Additive Oxide                               ______________________________________                                         92       43.1     43.1     11.0   2.8 La.sub.2 O.sub.3                         93       43.2     43.2     9.6    4.0 Y.sub.2 O.sub.3                          94       40       40       10     10 ZnO                                       95       40.7     40.7     14.3   7.3 BaO                                      96       40.4     40.4     10     9.2 ZnO                                      ______________________________________                                    

Table XII records electrical resistivity determinations measured at room temperature utilizing a Simpson ohm-meter. Finally, transition temperature determinations via differential thermal analysis, and refractive index measurements are recited.

                  TABLE XII                                                        ______________________________________                                                   Resistivity                                                          Example No.                                                                              (ohms)       T.sub.g    n.sub.D                                      ______________________________________                                         92        9.3 × 10.sup.5                                                                        --         --                                           93        1.3 × 10.sup.8                                                                        --         --                                           94        1.4 × 10.sup.8                                                                        --         --                                           95        --           178° C.                                                                            1.725                                        96        --           170° C.                                                                            1.720                                        ______________________________________                                    

Table XIII sets forth a group of compositions, expressed in weight percent on the oxide basis as calulated from the batch, of stable glasses falling within area ABCDEF of FIG. 8 along with a visual description of the glass prepared. Melting of the batch ingredients and forming of the molten batches were carried out in a manner similar to that described above with respect to the working examples of Table I. That is, the batches were compounded, placed into 96 percent silica crucibles, and melted for about 10 minutes at 900° C. The melts were poured onto a steel slab and quenched under the pressure of a graphite block into a thin plate of about 1 mm thickness. The batch materials employed were NH₄ H₂ PO₄, CuF₂, and NH₄ F.HF.

Table XIIIA reports the compositions as calculated in terms of mole percent and also includes electrical resistivity measurements (ohm cm) conducted at room temperature (˜25° C.) at 120 Hz, 1 KHz, and 10 KHz utilizing painted silver electrodes.

                  TABLE XIII                                                       ______________________________________                                         Example No.                                                                             Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                       F     Visual Appearance                                ______________________________________                                         97       12      77     11    Dark glass                                       98       16      37     47    Dark glass                                       99        5      90      5    Dark, sticky glass                               100       7      83     10    Dark, sticky glass                               101       6      77     17    Dark, sticky glass                               102      18      76      6    Dark glass                                       103      53      39      8    Dark, partly devi-                                                             trified glass                                    ______________________________________                                    

                  TABLE XIIIA                                                      ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                        F    120Hz  1KHz   10KHz                                ______________________________________                                         97     7       45      48   7 × 10.sup.7                                                                    6.8 × 10.sup.7                                                                  5.8 × 10.sup.7                 98     4       9       87   --     --     2.6 × 10.sup.7                 99     4       68      28   6.6 × 10.sup.5                                                                  6.3 × 10.sup.5                                                                  6.1 × 10.sup.5                 100    4       50      46   1.9 × 10.sup.6                                                                  1.9 × 10.sup.6                                                                  6.5 × 10.sup.5                 101    3       37      60   1.3 × 10.sup.7                                                                  1.3 × 10.sup.7                                                                  1.1 × 10.sup.7                 102    13      56      31   --     --     4.9 × 10.sup.7                 103    34      25      41   --     --     5.8 × 10.sup.7                 ______________________________________                                    

Table XIV lists a number of compositions, reported in terms of weight percent on the oxide basis as calculated from the batch, of relatively stable glasses encompassed within the area ABCDEF of FIG. 9 accompanied with a visual description of each glass prepared. The melting of the batch ingredients and the forming of the resultant melt were undertaken in like manner to that described immediately above with regard to Table XIII. The batch ingredients included NH₄ H₂ PO₄, CuF, CuCl, and NH₄ F.HF. The quantities of the batch components were adjusted such that equal molar amounts of fluoride and chloride were present in the batch.

Table XIVA recites the compositions as calculated in terms of mole percent and lists electrical resistivity determinations (reported in ohm cm) measured at room temperature (˜25° C.) at 120 Hz, 1 KHz, and 10 KHz utilizing painted silver electrodes.

                  TABLE XIV                                                        ______________________________________                                         Example No.                                                                             Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                        F    Cl   Visual Appearance                           ______________________________________                                         104      55      34      3.8  7.2  Light amber glass                           105      62      19      6.5  12.5 Dark, partly                                                                   devitrified glass                           106      41      25      11.5 21.5 Yellow glass                                107      74      18      2.8  5.2  Dark surface                                                                   devitrified glass                           108      51      34      5.2  9.8  Amber, partly                                                                  devitrified glass                           109      56      19      8.7  16.3 Dark glass                                  ______________________________________                                    

                  TABLE XIVA                                                       ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                       F   Cl  120Hz  1KHz   10KHz                              ______________________________________                                         104    37      23     20  20  3.7 × 10.sup.5                                                                  1.8 × 10.sup.5                                                                  4.4 × 10.sup.4               105    36      8      28  28  2.0 × 10.sup.3                                                                  1.9 × 10.sup.3                                                                  1.1 × 10.sup.3               106    17      11     36  36  3.4 × 10.sup.3                                                                  3.4 × 10.sup.3                                                                  2.7 × 10.sup.3               107    54      14     16  16  8.6 × 10.sup.4                                                                  8.1 × 10.sup.4                                                                  7.7 ×10.sup.4                108    31      21     24  24  3.9 × 10.sup.4                                                                  3.2 × 10.sup.4                                                                  1.1 × 10.sup.4               109    27      9      32  32  4.4 × 10.sup.4                                                                  4 × 10.sup.4                                                                    4 × 10.sup.4                 ______________________________________                                    

Table XV records exemplary glasses, stated in terms of weight percent on the oxide basis as calculated from the batch, of relatively stable glasses having compositions within the area ABCDEF of FIG. 10 and includes a visual description of each glass prepared. The melting of the batch materials and the forming of the molten batch into thin sheet were conducted in accordance with the method described with reference to Table XIII. NH₄ H₂ PO₄, CuF₂, CuBr, and NH₄ F.HF comprised bath ingredients therefor. The quantities of chloride and fluoride were carefully controlled such that equal molar amounts of each were present in the batch.

Table XVA lists the glasses as calculated in terms of mole percent and also reports electrical resistivity data (expressed as ohm cm) measured at room temperature (˜25° C.) at 120Hz, 1KHz, and 10KHz utilizing painted silver electrodes.

                  TABLE XV                                                         ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                        F    Br   Visual Appearance                             ______________________________________                                         110    46      34      3.8  16.2 Yellow, sticky glass                          111    47      19      6.3  27.7 Amber glass                                   112    24      46      5.4  24.6 Amber glass                                   113    36      28      6.9  20.1 Yellow-green glass                            114    17      58      4.8  20.2 Dark glass                                    115    74      18      1.5  6.5  Dark glass                                    116    51      34      3    12   Yellow, amber                                                                  sticky glass                                  117    56      19      5    20   Red, amber glass                              118    31      48      4    17   Amber glass                                   ______________________________________                                    

                  TABLE XVA                                                        ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                       F   Br  120Hz  1KHz   10KHz                              ______________________________________                                         110    33      25     21  21  1.9 × 10.sup.4                                                                  1.5 × 10.sup.4                                                                  9.5 × 10.sup.3               111    29      11     30  30  1.3 × 10.sup.3                                                                  2.6 × 10.sup.3                                                                  3.5 × 10.sup.3               112    16      32     26  26  3.1 × 10.sup.7                                                                  2.7 × 10.sup.7                                                                  1.6 × 10.sup.7               113    21      17     31  31  4.9 × 10.sup.3                                                                  2.5 × 10.sup.3                                                                  1.2 × 10.sup.3               114    12      40     24  24  --     --     1.4 × 10.sup.7               115    64      16     10  10  4.1 × 10.sup.5                                                                  4.1 × 10.sup.5                                                                  4.0 × 10.sup.5               116    40      27     17  17  6 × 10.sup.4                                                                    3.6 × 10.sup.4                                                                  2.7 × 10.sup.4               117    40      14     23  23  2.2 × 10.sup.3                                                                  2.0 × 10.sup.3                                                                  1.7 × 10.sup.3               118    17      37     23  23  1.0 ×  10.sup.7                                                                 9.8 × 10.sup.6                                                                  7.7 × 10.sup.6               ______________________________________                                    

Table XVI lists a number of working examples, recorded in terms of weight percent on the oxide basis as calculated from the batch, of relatively stable glasses having compositions included within the area ABCDEF of FIG. 11 along with a visual description of each glass body. The melting of the batch materials and the pressing of the melt into thin sheet were carried out in a manner similar to that described above with respect to Table XIII. The batch ingredients for the glasses included NH₄ H₂ PO₄, CuF₂, CuI, and NH₄ F.HF. The contents of fluoride and iodide were so controlled as to incorporate equal molar amounts of each into the batch.

Table XVIA recites the glasses as calculated in terms of mole percent and also tabulates electrical resistivity determinations (reported in ohm cm) measured at room temperature (˜25° C.) at 120Hz, 1KHz, and 10KHz employing painted silver electrodes.

                  TABLE XVI                                                        ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                        F   I    Visual Appearance                              ______________________________________                                         119    74      18      1   7    Dark glass                                     120    51      34      2   13   Red-brown, partly                                                              devitrified glass                              121    56      19      3.2 21.8 Dark amber glass                               122    31      47      2.7 19.3 Light amber glass                              123    26      32      5.4 36.6 Amber, surface                                                                 devitrified glass                              124    13      76      1.5 9.5  Dark brown glass                               ______________________________________                                    

                  TABLE XVIA                                                       ______________________________________                                         Example                                                                        No.    Cu.sub.2 O                                                                             P.sub.2 O.sub.5                                                                       F   I   120Hz  1KHz   10KHz                              ______________________________________                                         119    69      17      7   7  9.8 × 10.sup.5                                                                  9.2 × 10.sup.5                                                                  8.6 × 10.sup.5               120    45      29     13  13  3.0 × 10.sup.5                                                                  1.7 × 10.sup.5                                                                  9.0 × 10.sup.4               121    45      15     20  20  2.4 × 10.sup.4                                                                  2.2 × 10.sup.4                                                                  2.0 × 10.sup.4               122    26      40     17  17  2.6 × 10.sup.5                                                                  2.1 × 10.sup.5                                                                  1.7 × 10.sup.5               123    18      24     29  29  2.2 × 10.sup.6                                                                  1.3 × 10.sup.6                                                                  1 × 10.sup.6                 124    12      68     10  10  --     --     1.4 × 10.sup.7               ______________________________________                                    

Table XVII reports several other glasses, expressed in weight percent on the oxide basis as calculated from the batch, having compositions within the base P₂ O₅ -Ag₂ O-X system, wherein X is selected from the group of Cl, Br, I, and equal molar amounts of Cl and I. The glasses were prepared in like manner to that described above with respect to the examples listed in Table XI except that no additive oxides were incorporated therein. Table XVII also records d.c. electrical resistivity measurements conducted at room temperature (˜25° C.) utilizing the three probe method.

                  TABLE XVII                                                       ______________________________________                                                                                Resistivity                             Example                                (ohm cm ×                         No.    Ag.sub.2 O                                                                             P.sub.2 O.sub.5                                                                       AgCl  AgBr  AgI  10.sup.4                                ______________________________________                                         125    59.7    36.5   3.8   --    --   173                                     126    57.2    35.1    7.7  --    --   73                                      127    54.8    33.5   11.7  --    --   49                                      128    52.1    31.9   16.0  --    --   26                                      129    46.5    28.5   25.0  --    --   8.6                                     130    41.1    25.2   33.7  --    --   3.2                                     131    58.9    26.1   --     5.0  --   152                                     132    52.7    32.3   --    15.0  --   41                                      133    37.1    22.8   --    40.1  --   2.7                                     134    57.9    35.8   --    --     6.3 81                                      135    50.9    31.1   --    --    18.0 27                                      136    23.1    15.2   --    25.0  2.7                                          137    41.2    25.3   12.7  --    20.8 2.2                                     138    44.2    27.2   10.8  --    17.8 8.6                                     139    51.6    31.6    6.4  10.4  29.8                                         ______________________________________                                     

We claim:
 1. Cuprous copper and/or silver halophosphate glasses having softening points less than about 400° C., coefficients of thermal expansion (25°-300° C.) in excess of about 180 ×10⁻⁷ /° C., and electrical resistivities when measured at room temperature of less than about 10⁸ ohm cm, said glasses consisting essentially of the stated proportions, expressed in terms of weight percent on the oxide basis as calculated from the batch, selected from the groups of:(a) compositions defined by area ABCD of FIG. 1; (b) compositions defined by area ABCD of FIG. 2; (c) compositions defined by area ABCDE of FIG. 3; (d) compositions containing at least 1% chloride and defined by area ABCD of FIG. 5; (e) compositions containing at least 1% bromide and defined by area ABCD of FIG. 6; (f) compositions containing at least 1% iodide and defined by area ABCDE of FIG. 7; (g) compositions defined by area ABCDEF of FIG. 8; (h) compositions defined by area ABCDEF of FIG. 9; (i) compositions defined by area ABCDEF of FIG. 10; (j) compositions defined by area ABCDEF of FIG.
 11. 2. Cuprous copper and/or silver halophosphate glasses according to claim 1 wherein a combination of two or three halides may be present in the compositions of the groups (a)-(j).
 3. Cuprous copper and/or silver halophosphate glasses according to claim 1 wherein copper is substituted in part for silver and vice versa in the compositions of groups (a)-(j).
 4. Silver halophosphate glasses according to claim 1 wherein the chloride content of the group (d) compositions is at least 5%.
 5. Silver halophosphate glasses according to claim 1 wherein the bromide content of the group (e) compositions is at least 5%.
 6. Silver halophosphate glasses according to claim 1 wherein the iodide content of the group (f) compositions is at least 5%.
 7. Cuprous copper halophosphate glasses according to claim 1 exhibiting thermochromic behavior consisting essentially of the state proportions, expressed in weight percent on the oxide basis as calculated from the batch, selected from the groups of:(a) compositions defined by the area ABCD of FIG. 1; (b) compositions defined by the area ABCD of FIG. 2; and (c) compositions defined by the area ABCDE of FIG.
 3. 